The present disclosure relates generally to insulated glass units, and more particularly, to improved multiple pane insulated glass units that can be used in a display cooler door assembly.
Refrigerated display coolers are used in convenience stores, markets, food vending operations, and the like, to keep products, for example beverages and perishable food products, cool. Typically, such display coolers have a refrigerated compartment and an opening that is sealed by a door that can be opened by a consumer to retrieve the desired product.
Refrigerated display coolers consume a considerable amount of electricity during operation. It is therefore desirable to employ technologies that reduce the display cooler's electricity usage to save on operating costs, improve energy efficiency and reduce the CO2 footprint (among others) of the cooler. One method of reducing the electricity usage is to make the refrigerated display cooler, itself, more thermally insulative. For example, more insulation could be added to the refrigerated compartment. However, the physical footprint of a display cooler is often constrained, and thicker insulation would mean reducing the total available storage space inside the cooler, thereby reducing the number of items for sale that can be stocked inside the cooler.
Another mechanism for improving thermal performance is to make the display cooler door more insulative. A typical display cooler door comprises a frame surrounding an insulated glass unit (IGU). An IGU typically comprises two or more sheets of glass sealed at their peripheral edges by a seal. The sheets of glass are spaced apart, and the space between each sheet of glass, once sealed, can be filled with an inert gas, such as argon or krypton. In doing so, the insulative or thermal performance of the display cooler door can be improved.
In addition to improving thermal performance, a display cooler door IGU that is more thermally insulative also needs to meet other design constraints. These constraints include: (1) minimized mass for stability purposes of the IGU and to reduce weight-based shipping costs; (2) maximized visible transmittance through the IGU so customers can see displayed products; (3) minimized door thickness to prevent storage space from being reduced (once the display door is closed) to maintain a constrained cooler footprint and to utilize existing hardware (for improved upgrade and cost control purposes for such potential retrofitting, among others); (4) robust mechanical design to prevent IGU breakage when the door is cycled during typical consumer interaction and usage thereof; and (5) minimized manufacturing cost, by using existing hardware, for example.
One way of improving the thermal performance of an IGU is to increase the number of glass panes from two to three. Although increasing the number of glass panes used in the IGU can improve the thermal performance of the IGU, conventional triple pane IGUs fail to meet the other design constraints, especially the weight and visibility constraints. Accordingly, a display cooler IGU that has improved thermal insulation properties and that can also satisfy the other design constraints is needed in the industry.